地震电磁卫星任务规划系统研究

地震电磁卫星任务规划是支持卫星在轨业务运控的核心环节. 通过对地震电磁卫星任务规划系统的研究, 提出了地震电磁探测卫星任务规划的基本原则, 设计了地震电磁探测卫星任务规划系统架构, 分析了系统功能需求和规划处理流程, 在此基础上对地震电磁卫星进行了原型实现.      

地震监测卫星——从太空预报地震

2008年5月12日14时28分发生的汶川地震,如果我们事先有该地区连续的空间监测的热和电磁效应的图像,可能会有预报.发展中国的地震电磁卫星对地观测技术,将伫间手段与地基监洲相结合,建立"天地一体化"的立体地震电磁监测系统,将明显增加地震前兆的信息量,为地震预测预报提供重要的科学依据.     

DEMETER卫星记录到的电离层加热现象

在法国DEMETER卫星运行期间, 地基电离层加热装置SURA和HAARP开展了一系列加热试验, 记录到各类电离层异常信息, 发现电离层加热过程中卫星观测的电离层扰动信号包括HF发射泵波及边带泵波、VLF人工源增强及频谱拓展、ULF/ELF/VLF调制波、ELF电磁扰动、ULF谐振波、等离子体特征参量扰动及高能粒子沉降等. 由于传播及耦合机制的差异, 发射泵波可以穿透电离层直达卫星高度, 其观测概率最高达到68%以上, 其他扰动受发射调制模式及当地电磁环境等影响,观测概率相对较低, 均在40%左右, 有些甚至是某次试验中出现的个别事例. 结合中国地震电磁监测试验卫星飞行轨道设计及载荷配置等,对未来开展加热试验进行了分析论证, 并参考DEMETER卫星试验结果给出了一些建议.      

航天测绘发展现状与展望

航天测绘是全球基础测绘的主要手段,包括卫星地形测量、卫星重力测量、卫星磁力测量、卫星测高、卫星海洋测量等。航天测绘工程的发展经历了“返回型测绘卫星”工程、“传输型测绘卫星”工程和部分“集成型测绘卫星”工程。首先梳理了国际卫星测量的发展历史和现状,阐述了我国航天测绘各个阶段所发挥的作用,并分析了存在的问题,最后对航天测绘的未来发展提出了思路。     

电磁监测试验卫星矢量磁场探测方法

电磁监测试验卫星是中国第一颗近地轨道电磁场科学探测试验卫星, 探测空间背景磁场是其重要任务之一. 空间背景磁场探测需要在卫星平台上对空间矢量磁场进行长期稳定准确探测, 电磁监测试验卫星采用磁通门磁强计和基于CPT效应的绝对磁场校准装置(Coupled Dark State Magnetometer, CDSM)分别探测空间相对矢量磁场以及绝对标量磁场, 通过数据处理, 使最终的矢量磁场探测数据具有准确性. 这种数据处理方法在理想模型下拥有解析解, 实施过程中载荷的噪声、 准确度及稳定性影响模型的准确性, 会产生数据校准误差. 通过对在轨磁场探测的模拟确定了这种数据处理方法的性能, 验证了在载荷设计性能的基础上电磁监测试验卫星的磁场探测可以实现1 nT的准确度.      

新疆于田7.2 级地震前的电离层电磁扰动

利用法国DEMETER 卫星观测的电磁、等离子体等参量的观测数据分析了2008 年3 月21日新疆于田7.2 级地震前离子温度Ti、离子密度Ni、甚低频(VLF) 磁场等出现的异常变化. Ti分析显示震中区上空出现的突变信号在更大空间多次重复出现, 作为地震异常的信度不高. 通过多次重访轨道对比发现H+ 离子密度整体变化形态一致, 但夏秋季节的峰值变化幅度是冬春季节的1 倍. 通过把2008 年的数据与2007 年和2006 年同期的重访轨道数据进行对比, 发现2008 年在于田地震前1 个月左右Ni 在峰值区呈现了显著增强的变化趋势, 并一直持续到地震前, 2008 年2 月以后的峰值幅度是其他两年同期的~1 倍多. 对于磁场频谱数据, 抽取了震中区域上空2000 km 范围内多个轨道的单频(400 Hz)信息, 并在研究区域统一纬度空间(0~60°N) 进行了时间序列对比, 结果发现地震前2 日内震中区域上空400 Hz 谱密度增加了近一个数量级, 反映空间存在明显的VLF 电磁辐射现象. 对于3 月20 日极低频段(ELF) 三分量电磁场的矢量分析显示观测时段内存在一些左旋极化电磁信号, 反映了空间电离层离子密度变化伴随ELF 电磁辐射信息. 综合分析认为, 这次地震前各参量的变化过程与目前地震孕育及电离层耦合机理相吻合.      

国外低成本卫星技术研究

1 低成本卫星内涵辨析 当前,低成本卫星仍是相对概念,一般由工业界和学术界以"低成本"(Low Cost)、"较低成本"(Lower Cost)或"降低成本"(Cost Reduction)等概指.国外研究界一般认为,低成本卫星是指全寿命周期成本显著低于同类卫星平均成本的卫星.每个卫星任务都有其特定的任务需求、项目管理和指南要求,这些要素决定了卫星应具备的功能及其实现途径.不同卫星的任务有效载荷显著不同,其性能指标也具有较大差异.因此,国外研究界认为,无法用定量化的方式定义低成本卫星,但基于数理统计分析方法可以对比确定属于低成本范畴的卫星项目.总结这些满足低成本条件的卫星项目研制期间所采用的技术手段,即可认为采用这些手段能比传统手段更有效地降低卫星成本.     

卫星技术的发展趋势与创新思路

卫星技术是空间系统的核心 ,其发展水平 ,决定了 2 1世纪初空间系统的总体能力。1　通信广播类卫星技术通信广播类卫星是国外最早进入商业化的卫星领域 ,但迄今为止 ,卫星通信在全世界整个通信市场中的渗透率大约只占2 % ,其近期目标是达到 5% ,未来主要将与地面通信手段竞争。而实现这些目标的关键是技术发展与创新。军事通信广播卫星 ,在战时通信容量骤增的情况下 ,主要存在通信容量不足、抗干扰能力差等问题。为解决这些问题 ,提出了如下通信广播类卫星技术发展和主要创新思路。1 .1　高、中、低轨道卫星并行发展对于非全球性应用 ,主要…     

为预报地震探路的张衡-1卫星升空

正2018年2月2日,张衡-1电磁监测试验卫星(CSES)由长征-2D运载火箭从酒泉卫星发射中心成功送入太空。这次发射的张衡-1卫星是我国地震立体观测体系第一个天基平台,即首颗观测与地震活动相关电磁信息的卫星,也是我国地球物理场探测卫星计划的首发星。旨在建造全球电磁场和电离层监测平台,对我国及其周边地区开展电离层多种物理量动态准实时监测,使我国首次具备全疆域和全球三维地球物理场动态监测能力。张衡-1卫星将尝试开展地震电磁信息分析研究,探索地震电离层响应变化的信息特征及其机理,为地震观测     

中国首颗电磁监测试验卫星全扫描

正2月2日,中国第一颗电磁监测试验卫星"张衡一号"在长二丁火箭的托举下,于酒泉卫星发射中心成功发射入轨。作为我国第一颗观测与地震活动相关电磁信息的卫星,"张衡一号"格外受人关注。它能不能预测地震?在世界上处于什么地位?有哪些技术上的创新突破?未来还会有更多电磁监测试验卫星吗?……发射前夕,"张衡一号"总指挥、总设计师袁仕耿对这颗卫星的功能作了最为凝练的总结:张衡一号卫星的任务是要做     

Surface latent heat flux anomalies quasi-synchronous with ionospheric disturbances before the 2007 Pu’er earthquake in China

One of various mechanisms of pre-earthquake lithosphere–atmosphere–ionosphere coupling as possible explanation of the seismo-ionospheric effects is connected with the release of latent heat. Abnormal variations of ionospheric electromagnetic parameters possibly related to the 2007 Ms 6.4 Pu’er earthquake in China were reported. This paper attempts to examine whether there were abnormal changes of surface latent heat flux (SLHF) linked with this pre-earthquake ionospheric disturbances. The spatio-temporal statistical analyzes of multi-years SLHF data from USA NCEP/NCAR Reanalysis Project reveal that local SLHF enhancements appeared 11, 10 and 7 days before the Pu’er earthquake, respectively. As contrasted to the formerly reported local ionospheric Ne enhancement 9 days before the shock observed by DEMETER satellite, it is discovered that the SLHF and Ne anomalies are quasi-synchronous and have good spatial correspondence with the epicentre and the local active faults. This is valuable for understanding the seismogenic coupling processes and for recognizing earthquake anomaly with multiple parameters from integrated Earth observation system.     

Seismo-ionospheric anomalies in total electron content of the GIM and electron density of DEMETER before the 27 February 2010 M8.8 Chile earthquake

In this paper we examine the pre-earthquake ionospheric anomalies by the total electron content (TEC) extracted from GIM (global ionospheric map) and the electron density (Ne) observed by the DEMETER (Detection of Electro-Magnetic Emissions Transmitted from Earthquake Regions) satellite during the 2010 M8.8 Chile earthquake. Temporal variations show the nighttime TEC and Ne simultaneously increase 9–19 days before the earthquake. A cross-comparison of data recorded during the period of 1 February to 3 March in 2006–2010 confirms the above temporal anomalies specifically appear in 2010. The spatial analyses show that the anomalies tend to appear over the epicenter.     

Electric field and ion density anomalies in the mid latitude ionosphere: Possible connection with earthquakes?

The problem of earthquake prediction has stimulated the search for a correlation between seismic activity and ionospherical anomalies. We found observational evidence of possible earthquake effects in the near-equatorial and low latitude ionosphere; these ionospheric anomalies have been proposed by Gousheva et al. [Gousheva, M., Glavcheva, R., Danov, D., Angelov P., Hristov, P., Influence of earthquakes on the electric field disturbances in the ionosphere on board of the Intercosmos-Bulgaria-1300 satellite. Compt. Rend. Acad. Bulg. Sci. 58 (8) 911–916, 2005a; Gousheva, M., Glavcheva, R., Danov, D., Angelov, P., Hristov, P., Kirov, B., Georgieva, K., Observation from the Intercosmos-Bulgaria-1300 satellite of anomalies associated with seismic activity. In: Poster Proceeding of 2nd International Conference on Recent Advances in Space Technologies: Space in the Service of Society, RAST ‘2005, June 9–11, Istanbul, Turkey, pp. 119–123, 2005b; Gousheva, M., Glavcheva, R., Danov, D., Angelov, P., Hristov, P., Kirov, B., Georgieva, K., Satellite monitoring of anomalous effects in the ionosphere probably related to strong earthquakes. Adv. Space Res. 37 (4), 660–665, 2006]. This paper presents new results from observations of the quasi-static electric field and ion density on board INTERCOSMOS-BULGARIA-1300 satellite in the mid latitude ionosphere above sources of moderate earthquakes. Data from INTERCOSMOS-BULGARIA-1300 satellite and seismic data (World Data Center, Denver, Colorado, USA) for magnetically quiet and medium quiet days are juxtaposed in time-space domain. For satellite’s orbits in the time period 15.09–01.10.1981 an increase in the horizontal and vertical components of the quasi-static electric field and fluctuations of the ion density are observed over zones of forthcoming seismic events. Some similar post effects are observed too. The emphasis of this paper is put on the anomalies which specify the mid latitude ionosphere. The obtained results contain important information because they confirm our previous results for near-equatorial and low latitude regions.     

Multi precursors analysis associated with the powerful Ecuador (MW = 7.8) earthquake of 16 April 2016 using Swarm satellites data in conjunction with other multi-platform satellite and ground data

After DEMETER satellite mission (2004–2010), the launch of the Swarm satellites (Alpha (A), Bravo (B) and Charlie (C)) has created a new opportunity in the study of earthquake ionospheric precursors. Nowadays, there is no doubt that multi precursors analysis is a necessary phase to better understand the LAIC (Lithosphere Atmosphere Ionosphere Coupling) mechanism before large earthquakes. In this study, using absolute scalar magnetometer, vector field magnetometer and electric field instrument on board Swarm satellites, GPS (Global Positioning System) measurements, MODIS-Aqua satellite and ECMWF (European Centre for Medium-Range Weather Forecasts) data, the variations of the electron density and temperature, magnetic field, TEC (Total Electron Content), LST (Land Surface Temperature), AOD (Aerosol Optical Depth) and SKT (SKin Temperature) have been surveyed to find the potential seismic anomalies around the strong Ecuador (M_w = 7.8) earthquake of 16 April 2016. The four solar and geomagnetic indices: F10.7, D_st, K_p and a_p were investigated to distinguish whether the preliminary detected anomalies might be associated with the solar-geomagnetic activities instead of the seismo-ionospheric anomalies. The Swarm satellites (A, B and C) data analysis indicate the anomalies in time series of electron density variations on 7, 11 and 12 days before the event; the unusual variations in time series of electron temperature on 8 days preceding the earthquake; the analysis of the magnetic field scalar and vectors data show the considerable anomalies 52, 48, 23, 16, 11, 9 and 7 days before the main shock. A striking anomaly is detected in TEC variations on 1 day before earthquake at 9:00 UTC. The analysis of MODIS-Aqua night-time images shows that LST increase unusually on 11 days prior to main shock. In addition, the AOD variations obtained from MODIS measurements reach the maximum value on 10 days before the earthquake. The SKT around epicentral region presents anomalous higher value about 40 days before the earthquake. It should be noted that the different lead times of the observed anomalies could be acknowledged based on a reasonable LAIC earthquake mechanism. Our results emphasize that the Swarm satellites measurements play an undeniable role in progress the studies of the ionospheric precursors.     

Investigation of the relationship between ionospheric foF2 and earthquakes

Variations of the ionospheric F2 region critical frequency (foF2) have been investigated statistically before earthquakes during 1980–2008 periods in Japan area. Ionosonde data was taken from Kokubunji station which is in the earthquake preparation zone for all earthquakes. Standard Deviations and Inter-Quartile Range methods are applied to the foF2 data. It is observed that there are anomalous variations in foF2 before earthquakes. These variations can be regarded as ionospheric precursors and may be used for earthquake prediction.     

大数据卫星传输系统的设计与实现

以地震数据卫星传输系统的工程实践为基础，总结了基于卫星，微波和基带信道的高速大数据传输系统的设计思想，阐明了系统设计的关键技术，给出了卫星、微波和基带一体化传输系统的实现过程及部分运行结果。     

A MLP neural network as an investigator of TEC time series to detect seismo-ionospheric anomalies

Anomaly detection is extremely important for earthquake parameters estimation. In this paper, an application of Artificial Neural Networks (ANNs) in the earthquake precursor’s domain has been developed. This study is concerned with investigating the Total Electron Content (TEC) time series by using a Multi-Layer Perceptron (MLP) neural network to detect seismo-ionospheric anomalous variations induced by the powerful Tohoku earthquake of March 11, 2011.     

Genetic algorithm for TEC seismo-ionospheric anomalies detection around the time of the Solomon (Mw = 8.0) earthquake of 06 February 2013

On 6 February 2013, at 12:12:27 local time (01:12:27 UTC) a seismic event registering M_w 8.0 struck the Solomon Islands, located at the boundaries of the Australian and Pacific tectonic plates. Time series prediction is an important and widely interesting topic in the research of earthquake precursors. This paper describes a new computational intelligence approach to detect the unusual variations of the total electron content (TEC) seismo-ionospheric anomalies induced by the powerful Solomon earthquake using genetic algorithm (GA). The GA detected a considerable number of anomalous occurrences on earthquake day and also 7 and 8 days prior to the earthquake in a period of high geomagnetic activities. In this study, also the detected TEC anomalies using the proposed method are compared to the results dealing with the observed TEC anomalies by applying the mean, median, wavelet, Kalman filter, ARIMA, neural network and support vector machine methods. The accordance in the final results of all eight methods is a convincing indication for the efficiency of the GA method. It indicates that GA can be an appropriate non-parametric tool for anomaly detection in a non linear time series showing the seismo-ionospheric precursors variations.     

月震特征及与地震的对比

月球内部结构是月球研究的热点问题，月震是研究月球内部结构的最佳手段之一.对月震数据及震源参数进行了再分析，在分析已有研究结果的基础上，对各类月震的信号特征、震源分布以及震源机制进行讨论，并将其与地震进行对比.研究发现，月震与地震有很多明显差异:月震信号持续时间较长，且深源月震与热月震具有波形匹配特征；探测到的月震多为深源月震，主要分布于月球正面的北东向和南西向；深源月震和热月震的发震时间都具有周期性，深源月震的周期性主要由地球对月球的潮汐引力以及太阳对月球轨道的扰动造成，且其发震位置具有丛集性，即在相同或相近位置重复发生，而热月震的周期性主要由于月球昼夜温度变化造成.      

Change in refractivity of the atmosphere and large variation in TEC associated with some earthquakes,observed from GPS receiver

The present study reports the analysis of GPS based TEC for our station Surat (21.16°N, 72.78°E) located at the northern crest of equatorial anomaly region in India at times close to some earthquake events (M ? 5) during the year 2009 in India and its neighbouring regions. The TEC data used in the study are obtained from GPS Ionospheric Scintillation and TEC Monitoring (GISTM) system. The TEC data has been analysed corresponding to 11 earthquakes in low solar activity period and quiet geomagnetic condition. We found that, out of 11 cases of earthquakes (M > 5) there were seven cases in which enhancement in TEC occurred on earthquake day and in other four cases there was depletion in TEC on earthquake day. The variation in refractivity prior to earthquake was significant for the cases in which the epicentre lied within a distance of 600 km from the receiving station. By looking into the features on temporal enhancement and depletion of TEC a prediction was made 3–2 days prior to an earthquake (on 28 October 2009 in Bhuj – India). The paper includes a brief discussion on the method of potentially identifying an impending earthquake from ionospheric data.